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COMPONENT DESCRIPTION: Control Box

Contactor:  A definite purpose contactor
connecting the compressor  and the remote
condenser fan motor to the power supply.
Circuit Board:  Controlling the ice machine
through sensors and relays. The sensors are for
ice level and water level.  The relays are for the
gear motor (with a built in time delay to clear the
evaporator of ice when the unit turns off) and for
the compressor. 

Transformer:  Supplies low voltage to the circuit
board.
Low Pressure Cut Out Switch: A manual  reset
control that shuts off the ice machine when the low
side pressure drops below a preset point, 0-4 psig.
Potential Relay:  The compressor start relay.
On/Off Switch:  Manual control for the machine.

ON/OFF SWITCH

LOW

PRESSURE

CUT OUT

SWITCH

POTENTIAL

RELAY

TRANSFORMER

CONTACTOR

CIRCUIT

BOARD

NM952

August  1993

Page 10

Содержание NM952

Страница 1: ...rmostatic expansion valve and R 22 as the refrigerant This manual was printed on recycled paper TABLE OF CONTENTS Installation For the Installer Specifications 2 Location 3 Two units on one bin 4 For...

Страница 2: ...e of the limitations is misuse and can void the warranty Model Number NM952AE 3A NM952WE 3A NM952AE 32A NM952WE 32A Dimensions w o bin W x D x H 21 x 24 x 27 same same same Basic Electrical 208 230 60...

Страница 3: ...ocations Be sure that the location for the machine is within the environmental limitations Storage Bin Tip the storage bin on its back using parts of the carton to protect the exterior finish Install...

Страница 4: ...FOR THE INSTALLER Location TWO UNITS ON ONE BIN ALLOW ROOM FOR AIR CIRCULATION AND SERVICE ACCESS DO NOT STACK ANYTHING IN FRONT OF THE MACHINE S NM952 August 1993 Page 4...

Страница 5: ...e cabinet The water pressure to all lines must always be above 20 psig and below 80 psig Drains Air Cooled Models There is one 3 4 FPT drain at the back of the cabinet the drain line is of the gravity...

Страница 6: ...machine requires a solid chassis to earth ground wire The ice maker should be connected to its own electrical circuit so it would be individually fused Voltage variation must remain within design lim...

Страница 7: ...late requirements 3 Have all the plumbing connections been made and checked for leaks 4 Has the machine and bin been leveled 5 Is there a minimum of 6 clearance at the back of the machine for proper s...

Страница 8: ...valve will open and warm water will be discharged into the drain 5 The unit should soon be making ice if desired the low side pressure may be checked it should be 25 psig or 2 psig The suction line te...

Страница 9: ...of Will shut the machine off it there is none Ice Discharge Chute Directs the ice produced by the evaporator into the storage bin Ice Level Sensor An electronic eye it senses the presence of ice in t...

Страница 10: ...a built in time delay to clear the evaporator of ice when the unit turns off and for the compressor Transformer Supplies low voltage to the circuit board Low Pressure Cut Out Switch A manual reset co...

Страница 11: ...ere the two seal faces meet Ice Sweep A plastic cap with fingers It revolves with the auger to sweep the ice into the ice chute Breaker Divider Where the ice is compressed and much of the extra water...

Страница 12: ...sts of The compressor relay opens The compressor contactor opens The compressor stops The auger motor is run by the circuit board for 2 more minutes clearing out ice in the evaporator and then The aug...

Страница 13: ...he bottom of the evaporator Reservoir overflow or evaporator condensation is routed to the drain Water cooled models have a separate water circuit for the cooling water it enters the fitting at the re...

Страница 14: ...pon the temperature of the evaporator warmer evaporators get more refrigerant and colder evaporators get less At the evaporator the refrigerant enters an area of relatively low pressure where it can e...

Страница 15: ...eaning solution Mix eight ounces of Scotsman Ice Machine Cleaner with three quarts of hot water The water should be between 90 115 degrees F 8 Slowly pour the cleaning solution into the water reservoi...

Страница 16: ...st two times per year A Check the bearing by removing the ice chute cover unscrewing the ice sweep removing the water shed unscrewing the breaker cover unscrewing the auger stud Inspect the assembly l...

Страница 17: ...condenser the condenser may appear to be clean on the surface but it can still be clogged internally Check with a flash light from the front to see if light can be seen though the condenser fins Reve...

Страница 18: ...off electrical power and turn off the water supply 1 To remove the auger remove the front and top panels 2 Remove 3 hex studs holding ice chute cover to ice chute and remove cover 3 Unscrew and remove...

Страница 19: ...it Replace the drier recover evacuate and weigh in the nameplate charge E Check the high pressure cut out if closed go to F if open check 1 The pressure control opens at 400 psig Check the high side...

Страница 20: ...n full light on the tester should be ON if not replace the circuit board If the bin full light on the tester is ON move the tester switch to bin empty the light on the tester should go OFF and the bin...

Страница 21: ...oil is open replace the contactor 3 Check the auger drive motor centrifugal switch If when the drive motor is running contact 4 black wire removed has no power and all of the above switches have been...

Страница 22: ...r leaks replace the water seal if found to be leaking 3 Check the low side pressure normal is about 25 psig If low assume a refrigerant leak locate repair and recharge If no leak the TXV may be restri...

Страница 23: ...e maker 8 Reverse to reassemble BIN CONTROLS Ice Level Sensors 1 Disconnect electrical power 2 Remove front panel 3 Remove control box cover 4 Locate ice chute at the base of the chute in front of and...

Страница 24: ...and damage a The bearing is pressed into the breaker to remove the bearing and replace it an arbor press is needed b Replace lower seals before installing new bearing in breaker Note seals must be pr...

Страница 25: ...r from evaporator e If the auger is stuck use a slide hammer type puller to pull on the auger at the threaded hole The size of that hole is 5 8 18 Inspect the auger the critical areas of the auger are...

Страница 26: ...n against it 3 The part of the water seal that rotates with the auger must also be replaced Remove the old part from the auger and clean the mounting area 4 Place a small bead of food grade silastic s...

Страница 27: ...in the liquid line 7 Evacuate the system until dehydrated then weigh in the nameplate charge Check for leaks 8 Install auger breaker breaker bearing assembly and ice discharge chute in reverse order...

Страница 28: ...emove top panel 2 Unplug the two fan motor wire leads from the fan motors 3 Remove the two hex head bolts from the top end of the fan motor assembly 4 Lift up and pull out the fan motor assembly 5 Rep...

Страница 29: ...y heat sink material Specifically Recover reclaim or recycle refrigerant Although the method chosen is up to the service company Scotsman recommends reclaim There are various mechanical devices that m...

Страница 30: ...the ice level sensors are properly aligned clean and not obstructed use the tester as follows Bin Control Note All testing is done with the electrical power on the master switch on and all reset switc...

Страница 31: ...ot replace the circuit board b Move the water switch on the tester to the Water position The No Water light on the board should go OFF If not replace the circuit board If the light does go off replace...

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